The Five Tenets of Dark Brotherhood

Tenet 1: Never dishonor the Night Mother. To do so is to invoke the Wrath of Sithis.
 
Tenet 2: Never betray the Dark Brotherhood or its secrets. To do so is to invoke the Wrath of Sithis.
            
Tenet 3: Never disobey or refuse to carry out an order from a Dark Brotherhood superior. To do so is to invoke the Wrath of Sithis.
         
Tenet 4: Never steal the possessions of a Dark Brother or Dark Sister. To do so is to invoke the Wrath of Sithis.
            
Tenet 5: Never kill a Dark Brother or Dark Sister. To do so is to invoke the Wrath of Sithis.